Aragon 2005 THX amp bias how to?

So today I learned that amp bias was even a thing. I can see I have pots on my amp, what can be gained by properly tweaking and calibrating the pots, and is this something needed to be checked every few years on an amp that's a few years old? And how exactly would I do this?

Aragon 2005 THX Ultra 2 Class A/B amp specs:

DESIGN 5-ch THX Ultra2 Amplifier

POWER OUPUT 200 watts/ch into 8 ohms at less than 0.03%

THD (20Hz-20kHz - 3 channels driven)

POWER OUTPUT 300 watts/ch into 4 ohms at less than 0.05% THD

FREQUENCY RESPONSE 20Hz-20kHz +0/-0.1dB 10Hz-100kHz +0/-0.5dB

TIM/DIM DISTORTION 0.00%

S/N RATIO 106dB A-weighted

DAMPING FACTOR 500 (8 ohms - 50Hz)

INPUT SENSITIVITY 100mV-1W / 1.42V-200W

INPUT IMPEDANCE 20k ohms

Aragon - 2005 (Klipsch)

All pictures here Aragon 2005 THX 5 channel amp - Album on Imgur

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.
 
Last edited:
If the amp is working properly, has not had a recent repair, the bias should not have changed.

If you are not familiar with the process, just check your heatsinks - if you can keep your hand on them for more than 10-15 seconds after the amp being idle or playing music for 30-mins - it is set fine for Class AB.
 
Spesifications says it runs 105W idle. that makes it around 90W dissipation from the amps outputstage. 54W on the right side and 36W on the left side. With those sinks, that amp would run somewhat hot. It looks as it is only 20mm fins. and "only" 370mm depth.
My 5ch honeybadger have just a tiny bit less heatsink pr ch (300x165x40mm) as this one use for 3 ch.
That one is running 120W dissipation from the outputstages (24W pr ch). and it runs 13c above ambient at idle.
 
Last edited: